OBSERVATIONS ON SOME BASAL FAILURES IN SHEETED EXCAVATIONS

IN EXCAVATIONS BELOW GROUNDWATER LEVEL, INSTABILITY OF THE BASE MAY RESULT FROM THE INFLOW OF WATER INTO THE EXCAVATION. THE MOST IMPORTANT FACTORS INFLUENCING THE STABILITY ARE THE GROUND WATER AND DETAILED SOIL CONDITIONS AT THE SITE. CONSTRUCTION PROBLEMS ENCOUNTERED IN EXCAVATIONS IN CLAY STRATA UNDERLAIN BY PERVIOUS WATER- BEARING LAYERS ARE DESCRIBED. THE REMEDIAL MEASURES ADOPTED IN EACH CASE ARE ALSO DISCUSSED. FROM A STUDY OF THE OBSERVATIONS MADE IN THE CASE RECORDS, IT IS SUGGESTED THAT EXCAVATION IN INTACT CLAYS MAY BE CARRIED OUT TO DEPTHS EXCEEDING THAT LIMITED BY THE RATIO OF T/H = 0.5, WHERE T IS THE DISTANCE FROM THE BOTTOM OF THE EXCAVATION TO THE TOP OF THE WATER BEARING STRATUM, AND H IS THE WATER HEAD AT THE TOP OF THE WATER BEARING STRATUM, PROVIDED THAT THE CLAY IS NOT DISTURBED DURING CONSTRUCTION SO THAT THE SHEAR STRENGTH OF THE CLAY IS PRESERVED. /CGRA/

• Authors:
  • Milligan, V
  • Lo, K Y
• Publication Date: 0

Media Info

• Serial:
  • CANADIAN GEOTECHNICAL JOURNAL
  • Issue Number: 0
  • Publisher: National Research Council of Canada

Subject/Index Terms

• TRT Terms: Clay; Clay water systems; Excavations; Flow; Foundations; Groundwater; Pervious soils; Stability (Mechanics); Streamflow; Subsurface drainage; Underground structures; Water
• Old TRIS Terms: Intact clays
• Subject Areas: Bridges and other structures; Construction; Geotechnology; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00230981
• Record Type: Publication
• Source Agency: CANADIAN GOOD ROADS ASSOCIATION
• Files: TRIS
• Created Date: Feb 12 1971 12:00AM